ok, so I have planned how to sort the longfall boots from portal 2, but the material I should use for the heel is evading me, I have considered getting the heels off of bocking stilts, but that seems a little inpractical, so now I am thinking more of a solid heel, would acrylic be strong enough for this, or would it need to me something else. It needs to be able to support my weight and be sturdy enough to walk on without falling over and breaking something! any help would be awesome! thanks!

If you made the heel thick enough, acrylic could be strong enough. Lexan (polycarbonate) would probably be better/safer. Also, lexan is more scratch resistant.

Large hunks of either can be pretty easily carved with rotary tools, and then polished with a combination of sandpapers and jewlers rouge to bring back the transparency. When carving, take care not to overheat the plastic, or it melts into goo.

Oh yeah, scuff up the bottom of the acrylic and put a piece of rubber on the bottom. I THINK superglue would hold it in place, but you'll want to do some tests. Throughout this build, keep safety as your top priority.